Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B7/00—Halogens; Halogen acids
  • C01B7/01—Chlorine; Hydrogen chloride
  • C01B7/03—Preparation from chlorides
  • C01B7/05—Preparation from ammonium chloride
  • C01B7/055—Preparation of hydrogen chloride from ammonium chloride
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
  • C01C1/00—Ammonia; Compounds thereof
  • C01C1/02—Preparation, purification or separation of ammonia
  • C01C1/026—Preparation of ammonia from inorganic compounds
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
  • C01C1/00—Ammonia; Compounds thereof
  • C01C1/02—Preparation, purification or separation of ammonia
  • C01C1/026—Preparation of ammonia from inorganic compounds
  • C01C1/028—Preparation of ammonia from inorganic compounds from ammonium sulfate or sulfite

Definitions

• This invention relates to a process for producing ammonia and hydrogen chloride using ammonium chloride as a raw material.
• the production of the hydrogen chloride and ammonia is carried out as follows: ammonium chloride and sodium hydrogen sulfate are mixed and heated to produce hydrogen chloride according to an Equation 1, and thereafter the reaction temperature is further raised to produce ammonia according to an Equation (2).
• the reaction of the Equation 1, or the reactions of the Equations 1 and 2 in this process are carried out in solid phase. Accordingly, the contact of the reaction products does not seem effective and therefore it is very difficult to completely carry out the reactions. Additionally, since the reaction of the Equation 2 is carried out at a temperature in the vicinity of the sublimation temperature of ammonium chloride, unreacted ammonium chloride at the Equation 1 sublimates as gaseous ammonium chloride which will be mixed into ammonia gas at the Equation 2.
• Recovering the thus mixed gaseous ammonium chloride is disadvantageous from a point of view of simplification of an apparatus for the reactions. Furthermore, the gaseous ammonium chloride attaches onto the inner surface of a upper section of a reactor, which becomes a cause of trouble. Moreover, if a larger amount of unreacted ammonium chloride is present, heat loss becomes greater by the amount corresponding to the amount of unreacted ammonium chloride. This is considerably disadvantageous from a stand point of thermal efficiency.
• a process wherein hydrogen chloride and ammonia are produced, using ammonium chloride as a raw material, by the steps of (1) carrying out the reaction of ammonium chloride with ammonium hydrogen sulfate in the state of molten salt to produce hydrogen chloride, and (2) heating the reaction system as the step (1) at a temperature of 300° C. or higher to produce ammonia gas.
• hydrogen chloride gas produced at the step (1) is separated from the reaction system, and ammonia gas produced at the step (2) is separated from the reaction system.
• a main object of the present invention is to provide an improved process for producing hydrogen chloride and ammonia, which overcomes drawbacks encountered in conventional processes for producing the same.
• Another object of the present invention is to provide an improved process for producing hydrogen chloride and ammonia, which is advantageous from an industrial stand point, as compared with the conventional process for producing the same.
• a further object of the present invention is to provide an improved process for producing hydrogen chloride and ammonia, in which a reaction can be effectively carried out with high yield of an objective reaction product, without rise of various problems caused under high temperature condition.
• a still further object of the present invention is to provide an improved process for producing hydrogen chloride and ammonia, in which a reaction is carried out in the state of molten salt under a relatively low temperature condition, whereby the contact of the raw materials in the reaction mixture can be improved, preventing unnecessary sublimation of materials in the reaction system.
• the process of producing ammonia and hydrogen chloride in accordance with the present invention comprises a first step represented by an Equation 3 which ammonium chloride is added to a molten salt of ammonium hydrogen sulfate to produce ammonium sulfate and hydrogen chloride, and a second step represented by an Equation 4 in which the thus produced ammonium sulfate is subjected to a thermal decomposition to produce ammonium hydrogen sulfate and ammonia.
• ammonium hydrogen sulfate and the molten salt of ammonium chloride are kept at a temperature within range from 150° to 280° C., preferably within a range from 200° to 260° C., to produce hydrogen chloride gas. If this temperature exceeds 280° C., the produced ammonium sulfate will decompose to produce ammonia gas, which is disadvantageous.
• the molten salt which has completed in reaction for producing hydrogen chloride is supplied for the second step.
• ammonium sulfate is kept at a temperature above the decomposition temperature thereof of 280° C., preferably within a range from 320° to 380° C., to produce ammonia gas. If this temperature exceeds 380° C., the decomposition reaction of ammonium hydrogen sulfate is caused to produce SO 3 gas.
• This SO 3 reacts with ammonia gas resulting from the decomposition of ammonium chloride in gas phase to produce solid ammonium hydrogen sulfate which will be attached in the surface of the piping of a reaction apparating, accompanying with similarly attached solid ammonium sulfate, which will become a cause of clogging of the piping of the reaction apparatus.
• the reaction apparatus it is preferable to expel ammonia gas by means of stirring, introducing air, steam, or an inert gas, or sucking it out.
• the molten salt of the ammonium hydrogen sulfate is again supplied to the first step, newly adding ammonium chloride to carry out the reaction for producing hydrogen chloride.
• the molten salt of ammonium hydrogen sulfate is used to be recirculated from the second step to the first step.
• the melting temperature of the ammonium hydrogen sulfate is 147° C.
• the mol ratio of ammonium chloride and ammonium hydrogen sulfate is 1:1.5 or more, in order to obtain molten salt which is high in fluidity.
• the rate of production of ammonia gas at the second step is high as compared with a conventional process using sodium hydrogen sulfate, and it is possible to carry out the reaction at a low temperature as compared with the same conventional process.
• the amount of ammonium chloride to sublimate can be reduced, and accordingly there is no fear of preventing heat transfer and clogging in piping the reaction apparatus, resulting from attaching of the ammonium chloride onto the inner wall surface of the reaction apparatus. This is considerably advantageous from an industrial standpoint.
• the mol ratio of ammonium chloride and ammonium hydrogen sulfate is 1:1.5-5.0. If the mol ratio is lower than 1:1.5, it is difficult to maintain the molten state, and whereas even if the mol ratio is higher than 1:5.0, an effect corresponding to such a high ratio cannot be expected. Therefore, more preferably the mol ratio is within a range of from 1:1.5-1:3.0.
• ammonium sulfate and/or a sulfate of alkali metal at the first step or the second step.
• ammonium sulfate it is desirable to increase the proportion of mol of ammonium hydrogen sulfate relative to ammonium chloride in order to maintain the molten state of this reaction system.
• ammonium sulfate By virtue of ammonium sulfate to be added, a larger amount of ammonia which is capable of decomposing than the equivalent amount of the prepared ammonium chloride is added to increase the rate of reaction, thereby producing ammonia in the equivalent amount with the prepared ammonium chloride.
• the mol ratio of ammonium chloride, ammonium hydrogen sulfate, and ammonium sulfate and/or the sulfate of alkali metal is preferably 1.0:1.5-10:0-1.0, and more preferably 1.0:1.5-4.0:0-0.5. If the amount of ammonium sulfate and/or the sulfate of alkali metal is much larger in the above-mentioned ratio, the rate of production of hydrogen chloride gas is lowered, which is disadvantageous.
• the yield of produced ammonia gas reached 90.6% relative to the prepared ammonium chloride.
• the yield of produced hydrogen chloride is similar to in the case of Experiment No. 4 in Example 1; however, the yield of produced ammonia gas is much improved as compared with in Experiment No. 4 in Example 1. This exhibits that the addition of ammonium sulfate contributes to an increase in the yield of produced ammonia.
• the yield of produced ammonia was 78.7% in 1 hour reaction time, 94.7% in 2 hours reaction time, and 98.8% in 2.5 hours reaction time.
• the yield was 69.0% in 1 hour reaction time, and 87.7% in 2.5 hours reaction time, under the same reaction conditions as in the above.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Analytical Chemistry (AREA)
• Catalysts (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Citations (5)

• 1979
  • 1979-06-05 JP JP54069424A patent/JPS5925723B2/ja not_active Expired
• 1980
  • 1980-05-29 US US06/154,469 patent/US4293532A/en not_active Expired - Lifetime
  • 1980-05-30 GB GB8017813A patent/GB2052464B/en not_active Expired
  • 1980-06-04 FR FR8012429A patent/FR2458509B1/fr not_active Expired
  • 1980-06-04 BE BE0/200877A patent/BE883626A/fr not_active IP Right Cessation
  • 1980-06-04 DE DE3021253A patent/DE3021253C2/de not_active Expired
  • 1980-06-05 IT IT22565/80A patent/IT1132076B/it active

Patent Citations (5)

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